================== NOTICE: THIS ABSTRACT WAS EXTRACTED FROM APPLICATION AND HAS NOT BEEN PROOFED BY AN SRA.WHEN THERE ARE PROBLEMS WITH THE APPLICATION SCANNING PROCESS, THE EXTRACTED TEXT MAY BE INCORRECT OR INCOMPLETE. ================== This proposal is to request support for a Keystone Symposia meeting entitled Lymphocyte Activation and Gene Expression, organized by Leslie J. Berg, Lawrence E. Samelson and Facundo D. Batista, which will be held in Breckenridge, Colorado from February 27 - March 4, 2010. Lymphocytes mediate the adaptive immune responses to antigens derived from infectious agents;transformed cells;transplanted organs;and, in the setting of autoimmunity, one's own cells. The study of lymphocyte activation and gene expression is central to understanding the complex biology of these cells and offers hope for regulating these cells in different clinical settings. Much has been learned in the past several decades in this field. Receptors, enzymes and adapter molecules have been identified, signaling cascades and networks have been defined, and the complex regulation of gene expression has been explored. Nonetheless many basic questions remain to be elucidated. Among several contentious areas of research that will be presented by experts at this meeting are the actual means by which antigen receptors initiate the activation process, how activation induces changes in signaling pathways, intracellular organelles and the cytoskeleton, and how changes in chromatin and transcriptional factors determine gene expression. The topics covered in the 2010 Keystone Symposia meeting on Lymphocyte Activation and Gene Expression have direct relevance to a number of clinically important areas, including autoimmunity, immunodeficiency diseases, transplantation immunology, tumor immunology, infectious diseases, and chronic inflammation. Moreover, these mechanisms and pathways represent a major source of target leads for the development of new therapeutics to treat immunological disorders.